From: Daniel Berger <djberg96@...>
Date: 2009-08-02T14:10:45+09:00
Subject: ffi, struct pointer question

Hi,

I've recently been trying to port some C code over to FFI. I'm trying
to figure out how to unravel the gr_mem group struct member. Any
suggestions?

require 'ffi'

module Sys
   class Admin
      extend FFI::Library

      class GroupStruct < FFI::Struct
         layout(
            :gr_name,   :string,
            :gr_passwd, :string,
            :gr_gid,    :int,
            :gr_mem,    :pointer
         )
      end

      attach_function :getgrgid, [:int], :pointer

      def self.get_group(gid)
         GroupStruct.new(getgrgid(gid))
      end
   end
end

# How do I unravel the gr_mem struct member?
struct = Sys::Admin.get_group(84)
p struct[:gr_mem]

Regards,

Dan